Vincenzo De Matteo1,2, Felipe Forero1, Sophia-Marlene Busch1, Philip Linke1, Peter Wilhelm1, Kristof Rademacher1, Thorsten Gehrke1, Mustafa Citak1

1Department of Orthopaedic Surgery, ENDO-Klinik Hamburg, Holstenstr, Hamburg, Germany
2Department of Public Health, Section of Orthopaedic Surgery, Federico II University of Naples, Naples, Italy

Keywords: Aseptic loosening, novel classification, novel index, revision arthroplasty, rotating hinge prosthesis, tibia.


Objectives: This study aims to identify anatomical variants of the proximal tibia shaft and to develop a novel classification system for proximal tibia.

Patients and methods: Between October 2019 and April 2020, a total of 200 patients with standard knee anteroposterior radiographs were included in this study. We measured the inner diameter of the tibia 16 cm distally from the tibial plateau and 3 cm distally from the tibial spine. The ratio between these two measurements was applied as the novel index ratio.

Results: A total number of 197 patients (100 males and 97 females) with a median age of 68 years (range, 21 to 89 years) were included in the final analysis. According to the 25th and 75th percentiles, three groups were clustered for each sex. A higher distribution of the type B pattern was found in female and male patients. However, type A with a narrow inner diaphyseal diameter was less common in female patients. The median intraobserver reliability for rater 1 was 0.998. The inter-observer reliability was high (intraclass correlation coefficient: 0.998). There was a moderate correlation between the anteroposterior (AP) diameter and height (r=0.568) and a low correlation between the AP diameter and weight (r=0.376). The novel index shows no significant correlation between the index ratio and height (r=0.082), weight (r=0.014) or body mass index (r=-0.038).

Conclusion: The novel classification presents three different types of tibia for each sex: type C has a wider inner diaphyseal diameter compared to type A with a narrow inner diaphyseal diameter. Type B has the widest distribution among the subjects.

Citation: Matteo VD, Forero F, Busch SM, Linke P, Wilhelm P, Rademacher K, Gehrke T, Citak M. Enhancing the radiological classification system from the distal femur to the proximal tibia. Jt Dis Relat Surg 2022;33(1):33-39.

Conflict of Interest

The authors declared no conflicts of interest with respect to the authorship and/or publication of this article.

Financial Disclosure

The authors received no financial support for the research and/or authorship of this article.